For developing WordPress with PHPStorm I seem to need Subversion 1.8 due to this notification:

Which shows this error:

It reads ´svn: E155021: This client is too old to work with the working copy at ‘/Users/andrea/dev/wp/vvv/www/wordpress-develop’ (format 31). You need to get a newer Subversion client. For more details, see http://subversion.apache.org/faq.html#working-copy-format-change´.